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    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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    <script>

        let a = 1
        let b = 2

        // 如何让a=b b=a的值

        console.log(a , b);
        let c =a
        
        
        a=b
        b=c
        console.log("a" ,a);
        console.log("b" ,b)
    </script>
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